Radeon RX 570 8 GB problem

Hello, I recently bought a Radeon RX 570 graphics card and wanted to switch from my old Nvidia Geforce 740 SC, this card has held me up for the longest time but is struggling recently with the stuff that I do now for college and gaming. So anyways I bought the Radeon card hoping the 8 gb card would be way the heck better than the 2gb card. In theory it should. Anyways when I went into installing the card, I made sure to completely erase all Nvidia drivers using DDU, turned off my computer and went to installing the Radeon card. I installed it and put everything else back together, turned it on and the blue light showed saying that I have enough power going to it. But here is what dumbfounded me, it did not want to recognise my BIOS or Dell splash screen. When I went crazy on pressing f2 an error message came up saying "Video Mode 103 is not supported by this video card." Plus on top of that when I went into getting all the drivers the Device manager kept up throwing code 43 error messages, it recognized that the card was installed and powered on but decided not to go ahead and use it. I did a lot of research and pretty much tried everything and I am giving up. I then got frustrated DDU all AMD drivers and plugged my old 740 card in and everything worked fine and perfectly like it was before. So I am at two options its either my motherboard is to old or my Radeon card is a dud. Did anyone have issues or have seen this recently?